1. Field
Exemplary embodiments of the invention relate to a silicon-containing negative active material, a method of preparing the silicon-containing negative active material, a negative electrode including the silicon-containing negative active material, and a lithium secondary battery including the negative electrode, and more particularly, to a silicon-containing negative active material including a coating layer that includes carbon and a metallic particle, a method of preparing the silicon-containing negative active material, a negative electrode including the silicon-containing negative active material, and a lithium secondary battery including the negative electrode.
2. Description of the Related Art
Lithium secondary batteries (also referred to as lithium ion batteries) have been utilized as the primary power source in small electronic products due to their stable charge-discharge behavior and high energy density.
Recently, there is a tendency that small mobile electronic products, e.g., smartphones, are equipped with a variety of functions, and have high performance. In addition, the need for large-scale electric power supply sources has significantly increased along with the commercialization of hybrid vehicles or electric vehicles. In order to meet such demands, there is an urgent need for a development of core materials of existing lithium secondary batteries, such as a negative electrode, a positive electrode, a separator, and an electrolyte, in order to significantly improve the performance thereof.
Among these, the development of a novel negative electrode material is very important since it may result in the development of lithium secondary batteries of high energy density by increasing a specific-capacity of the batteries.
The development of various negative electrode materials, such as silicon, germanium, tin or tin oxide, and iron oxide has continuously been conducted. Among the negative electrode materials, silicon materials have been a subject of focused research and development, due to its high theoretical capacity (3580 milliampere-hours per gram, mAhg−1 as in the state of Li15Si4).
In general, conventional silicon materials were coated with electrical conductive carbon to improve electrical conductivity.